一(yi)、提(ti)高(gao)黑(hei)色金(jin)屬的防腐(fu)(fu)(fu)蝕(shi)能(neng)力;目前沖壓件中大(da)量使用(yong)的材(cai)料是碳鋼,如傳動鎖(suo)閉器、襯鋼等。對(dui)碳鋼而(er)言,如何提(ti)高(gao)防腐(fu)(fu)(fu)蝕(shi)性是影響其使用(yong)壽命的關(guan) 鍵(jian)。由于經常接(jie)觸雨水和日光(guang),原因一(yi)是可(ke)能(neng)PVC型材(cai)在老化過程(cheng)中,在光(guang)和熱作(zuo)用(yong) 下表面會游離出HCL,其對(dui)鍍鋅層(ceng)有極強腐(fu)(fu)(fu)蝕(shi)作(zuo)用(yong),這就能(neng)解釋為什么腐(fu)(fu)(fu)蝕(shi)發生(sheng)在與PVC型材(cai)接(jie)觸表面上;
二(er)、是由于(yu)鍍(du)層(ceng)太薄。據英國(guo)有關(guan)標準,對(dui)鍍(du)鋅(xin)層(ceng)在惡劣條件下使(shi)(shi)用除(chu)了(le)中(zhong)性(xing)鹽(yan)霧(wu)(wu)試(shi)(shi)驗(yan)(yan)要達到96小(xiao)(xiao)時外,還要求(qiu)鍍(du)鋅(xin)層(ceng)厚度(du)不低于(yu)40μm。現行國(guo)內(nei)標準往往只(zhi) 考(kao)慮鹽(yan)霧(wu)(wu)試(shi)(shi)驗(yan)(yan)時間,而不考(kao)慮鍍(du)層(ceng)厚度(du)。如鈍(dun)化(hua)膜完整良好,10μm左右的(de)(de)鍍(du)層(ceng)就能通過96小(xiao)(xiao)時的(de)(de)中(zhong)性(xing)鹽(yan)霧(wu)(wu)試(shi)(shi)驗(yan)(yan),一(yi)但鈍(dun)化(hua)膜素損(sun)壞(huai)就很容易產生銹蝕。國(guo)內(nei)電 鍍(du)行業普遍認為,96小(xiao)(xiao)時鹽(yan)霧(wu)(wu)試(shi)(shi)驗(yan)(yan)僅(jin)是試(shi)(shi)驗(yan)(yan)鍍(du)鋅(xin)鈍(dun)化(hua)膜的(de)(de)防護性(xing)能測試(shi)(shi),另外還根據使(shi)(shi)用環(huan)(huan)境(jing)規(gui)定鍍(du)鋅(xin)層(ceng)的(de)(de)厚度(du)分為三(san)等(deng):優良環(huan)(huan)境(jing)、一(yi)般環(huan)(huan)境(jing)、惡劣環(huan)(huan)境(jing),其(qi)鍍(du) 鋅(xin)的(de)(de)厚度(du)分別(bie)為61μm、121μm和(he)24μm。
沖(chong)(chong)壓(ya)所使用的(de)(de)模(mo)具稱為沖(chong)(chong)壓(ya)模(mo)具,簡稱沖(chong)(chong)模(mo)。沖(chong)(chong)模(mo)是將材料(金屬或非(fei)金屬)批量加工(gong)(gong)成所需(xu)沖(chong)(chong)件的(de)(de)專用工(gong)(gong)具。沖(chong)(chong)模(mo)在沖(chong)(chong)壓(ya)中至關重要(yao)(yao),沒有(you)(you)(you)符(fu)合要(yao)(yao)求(qiu)的(de)(de)沖(chong)(chong)模(mo),批量 沖(chong)(chong)壓(ya)生產就難以進(jin)(jin)行;沒有(you)(you)(you)先進(jin)(jin)的(de)(de)沖(chong)(chong)模(mo),先進(jin)(jin)的(de)(de)沖(chong)(chong)壓(ya)工(gong)(gong)藝就無法(fa)實現。沖(chong)(chong)壓(ya)工(gong)(gong)藝與模(mo)具、沖(chong)(chong)壓(ya)設備和沖(chong)(chong)壓(ya)材料構成沖(chong)(chong)壓(ya)加工(gong)(gong)的(de)(de)三要(yao)(yao)素,只有(you)(you)(you)它們相(xiang)互結(jie)合才能得(de)出沖(chong)(chong) 壓(ya)件。